In recent years, systems in which a television and a theater device are connected to each other via an optical digital cable and the television audio is outputted from a speaker of the theater device have been increasing. For example, Patent Literature 1 (Japanese Laid-Open Patent Publication No. 2010-205136) discloses an audio read-out device that performs audio read-out of text. Patent Literature 1 discloses that when an audio output device and the audio read-out device are connected to each other via a dedicated line or a network, the audio read-out device may output a read-out audio signal desired to be outputted, to the external audio output device via the dedicated line or the network. It is conceivable that such a technology is applied to a television, which is an audio read-out device, and a theater device, which is an audio output device.